Function xcb::ffi::xproto::xcb_change_save_set_checked

pub unsafe extern "C" fn xcb_change_save_set_checked(
    c: *mut xcb_connection_t, 
    mode: u8, 
    window: xcb_window_t
) -> xcb_void_cookie_t

Changes a client's save set

TODO: explain what the save set is for.

This function either adds or removes the specified window to the client's (your application's) save set.